Help! I'm just a beginner, can someone help me take a look? Thank you!

Projects General Guidance
1 
#include<DHT.h>
#include <Wire.h>
#include<BH1750.h>
#include<SoftwareSerial.h>
#include<U8glib.h>
#include <IRremote.hpp>
U8GLIB_SSD1306_128X64 u8g(52, 51, 11, 10, 9);
BH1750 ls;
DHT dht(7,DHT11);
#define OLED_RESET 4  
int page=1;
void setup() {
  // put your setup code here, to run once:
  pinMode(2,INPUT);pinMode(3,INPUT);pinMode(5,INPUT);pinMode(6,INPUT);
  pinMode(7,INPUT);pinMode(8,INPUT);pinMode(13,OUTPUT);
  Serial.begin(115200);Wire.begin();
  Serial3.begin(38400);
  IrReceiver.begin(4, ENABLE_LED_FEEDBACK);
  dht.begin();ls.begin();
  digitalWrite(13,HIGH);
}
void playsound(int f,int d){
  tone(13,f);
  delay(d);
  noTone(13);
  digitalWrite(13,HIGH);
}
void buttonc(){
  int nowmess=0;
  if(digitalRead(3)==HIGH){
    Serial.println("forward");
    page++;
    playsound(392,50);
    while(digitalRead(3)==HIGH)delay(100);
    nowmess=2;
    delay(100);
  }else if(IrReceiver.decode()){
    if(IrReceiver.decodedIRData.command==0xEA41){
      page--;
      playsound(392,50);
    }else if(IrReceiver.decodedIRData.command==0xCA41){
      page++;
      playsound(392,50);
    }
    while(IrReceiver.decode()){
      IrReceiver.resume();
      delay(100);
    }
    IrReceiver.resume();
  }
  if(page<=0)page=3;
  if(page>3)page=1;
}
float vol,h,t;
int mode=1,noid,mot,light,P;
void getppm(){
  vol = getVoltage(1);//MQ135->A1
  Serial.print(vol);Serial.print(" ");
}
float getVoltage(int pin){
  return (analogRead(pin)*0.004882814);
}
void getnoise(){
  noid=analogRead(2);
  Serial.print(noid);Serial.print(" ");
}
void getht(){
  h = dht.readHumidity();
  t = dht.readTemperature();
  Serial.print(h);Serial.print(" ");Serial.print(t);Serial.print(" ");
}
void getman(){
  mot=digitalRead(8);
  Serial.print(mot);Serial.print(" ");
}
void getli(){
  light=ls.readLightLevel();
  Serial.println(light);
}
int olda=1,oldb=1;
void turnsol(){
  int na=digitalRead(5),nb=digitalRead(6);
  int res=(na!=olda||nb!=oldb)&&(olda==1&&na==0)?oldb*2-1:0;
  olda=na;oldb=nb;
  mode+=res;
  if(mode<1)mode=3;
  if(mode>3)mode=1;
}
void drawpage1(){
  u8g.setFont(u8g_font_unifont);
  u8g.setColorIndex(1);
  u8g.setFont(u8g_font_5x7r);
  u8g.drawStr(10, 10, "PPM:");u8g.setPrintPos(90,10);u8g.print(vol);
  u8g.drawStr(10, 20, "volume:");u8g.setPrintPos(90,20);u8g.print(noid);
  u8g.drawStr(10, 30, "humidity:");u8g.setPrintPos(90,30);u8g.print(h);
  u8g.drawStr(10, 40, "temperature:");u8g.setPrintPos(90,40);u8g.print(t);
  u8g.drawStr(10, 50, "human infrared:");u8g.setPrintPos(90,50);u8g.print(mot);
  u8g.drawStr(10, 60, "brightness:");u8g.setPrintPos(90,60);u8g.print(light);
}
void drawpage2(){
  u8g.setFont(u8g_font_unifont);
  u8g.setColorIndex(1);
  u8g.setFont(u8g_font_5x7r);
  u8g.drawStr(10, 10, "bluetooth:");
  if(digitalRead(12)==HIGH)u8g.drawStr(60, 10, "connected");
  else u8g.drawStr(60, 10, "disconnected");
}
void drawpage3(){
  u8g.setFont(u8g_font_unifont);
  u8g.setColorIndex(1);
  u8g.setFont(u8g_font_6x13r);
  u8g.drawStr(10, 10, "mode:");
  if(mode==1)u8g.drawStr(50, 30, "AUTO");
  if(mode==2)u8g.drawStr(50,30,"REST");
  if(mode==3)u8g.drawStr(50,30,"SPORTS");
}
void loop() {
  // put your main code here, to run repeatedly:
  getppm();
  getnoise();
  getht();
  getman();
  getli();
  buttonc();
  if(page==3)turnsol();
  u8g.firstPage();
  do{
    if(page==1)drawpage1();
    if(page==2)drawpage2();
    if(page==3)drawpage3();
  }while(u8g.nextPage());
  if(page==1||page==2)delay(500);
  else delay(50);
}

I don't know why, but my buzzer (port 13) keeps ringing even though the playsound function hasn't been triggered. Can someone help me take a look? Thank you!

2

What type of buxxer is it ?

If it is an active buzzer then connecting it to 5V will cause it to buzz at a fixed frequency. No software needed. If it is a passive type then you need software such as the Tone library to make it sound a tone and you can control its frequency

3

Umm...Perhaps it's an active buzzer.

4

Leave it connected between pin 13 and GND and run the Blink example sketch. If it buzzes then it is an active buzzer

5

Yes, it's an active buzzer

6

oh,i have solved it.thanks!

7

How?

Did you change the active buzzer to a passive buzzer or change playsound(frq, dur); to digitalWrite(pin, HIGH)? Removed all tone() calls?